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8.99+0.1=
1-数学公式=
5-5÷2.5=
0、5×2.4=
0.1÷0.01=
0.43×(2.7+7.3)=
1.206×0.8≈(得数用四舍五入法凑整到百分位)
2998÷31≈(估算)

解:(1)8.99+0.1=9.09;
(2)1-=
(3)5-5÷2.5=3;
(4)0.5×2.4=1.2;
(5)0.1÷0.01=10;
(6)0.43×(2.7+7.3)=4.3;
(7)1.206×0.8≈0.96;
(8)2998÷31≈100.
分析:(1)根据小数的加法法则计算;
(2)根据分数的减法法则计算;
(3)先算除法,再算减法;
(4)根据小数的乘法法则计算;
(5)先算括号里面的加法,再算括号外面的乘法;
(6)根据小数的乘法法则计算,再得数用四舍五入法到百分位;
(7)将2998÷31看作3000÷30,根据除法法则计算进行估算
点评:综合考查了四则运算,解题的关键是熟练掌握运算法则,同时不要弄错运算顺序,看清题目的要求.
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